Overview of the specialty
A pension is a promise of income in the event of old age, disability or death whose cost depends on variables nobody controls: how long the pensioner will live, how salaries will grow, what inflation will be and what return the assets will earn over decades. The pension actuary turns that uncertainty into present figures: a liability on the balance sheet, a contribution that funds it, an annuity that a balance can buy. They work in social security (IMSS, ISSSTE, state and university systems) and in private company plans, with the Afores (retirement fund managers) and pension insurers as a bridge.
Two regimes coexist at the IMSS. Ley 73 is defined benefit: the pension is calculated from the average salary of the last 250 weeks and the weeks of contributions, with a minimum of 500. Ley 97, in force since July 1, 1997, is defined contribution: each worker accumulates savings in an individual account managed by an Afore and invested in SIEFORES (retirement fund investment companies). Anyone who contributed before that date can choose their regime on retirement, so retirement advice, including Modalidad 40 (voluntary continuation), remains an active market.
The reform published in the DOF (Official Gazette) on December 16, 2020 (in force since 2021) raises the contribution to the individual account from 6.5% to 15% of the contribution base salary between 2023 and 2030, funded mainly by the employer; it lowered the required weeks from 1,250 to 750 in 2021, with increases of 25 per year up to 1,000 in 2031; it made the guaranteed minimum pension variable and capped Afore fees. The decree of May 1, 2024 created the Fondo de Pensiones para el Bienestar (Pension Fund for Wellbeing, the Bienestar Fund), a trust with Banco de México as trustee that tops up the pension of those who retire at age 65 under Ley 97 or with ISSSTE individual accounts, up to a threshold of 16,777.68 pesos a month in 2024, updated to 17,885.85 pesos in 2026.
Private plans exist because the public pension rarely replaces the final salary of a middle manager, and because the LFT (Federal Labor Law) requires a seniority premium to be paid to every permanent employee. Many companies have moved to defined contribution or hybrid schemes to limit their risk, but they retain obligations that must be valued every year under NIF D-3 (or IAS 19). That recurring work, together with plan design and plan registration with CONSAR (National Retirement Savings Commission), supports a large share of actuarial consulting in the country.
Key roles
Valuation of DB, DC and hybrid plans
Calculates the defined benefit obligation, net periodic cost and remeasurements for pension plans, seniority premiums and termination benefits. The report feeds the notes to the financial statements under NIF D-3, IAS 19 or US GAAP (ASC 715).
Plan design and redesign
Defines benefit formulas, eligibility, vesting and employer and employee contributions. Quantifies the cost of converting a defined benefit plan into a defined contribution or hybrid plan while respecting accrued rights, and projects the replacement rate for each group.
IMSS retirement advice
Estimates the Ley 73 pension and compares it with the Afore balance under Ley 97. Assesses whether Modalidad 40 (voluntary continuation with a salary of up to 25 UMA) is worthwhile; its contribution rate rises every year until 2030 and its effect only reaches the average of the last 250 weeks.
Life annuities and pension insurance
At the insurers that write the pension insurance arising from the social security laws, prices the annuity purchased by the monto constitutivo (annuity purchase amount), sets up the mathematical pension reserve and checks the matching of cash flows and assets.
Fund investment and ALM
Designs the investment policy of company pension funds with asset-liability studies: duration of the obligation, cash flow profile and the sponsor’s risk tolerance. At the Afores, takes part in setting the glide paths of the generational SIEFORES, which reduce risk as each cohort approaches retirement.
Social security valuation
Projects income, expenditure and reserves of public insurance schemes with open group models and calculates equilibrium premiums and sufficiency periods for the IMSS, the ISSSTE, state pension systems and public universities.
Techniques, models and formulas
The toolbox combines classic actuarial mathematics (actuarial present values, multiple decrement tables) with financial projection and simulation. In company plans the projected unit credit method rules; in individual accounts and social security, long-term projections and scenario analysis dominate.
Projected unit credit method (PUC)
Assigns to each year of service one unit of benefit calculated with the salary projected to the payment date; the obligation is the accrued portion of the present value of the projected benefit. It is the method required by NIF D-3 and IAS 19 for defined benefits.
Multiple decrement tables
Combine death, disability, turnover and retirement to estimate the probability of reaching the payment age in service. Turnover is usually the assumption that moves the seniority premium the most; mortality, the one that moves annuities.
Mortality with improvement
Static mortality tables understate the cost of an annuity because younger generations will live longer. Improvement scales or generational tables are applied and longevity scenarios are tested.
Individual account projection
Simulates contributions, returns net of fees and contribution density to estimate the balance, the replacement rate and the probability of needing the guaranteed minimum pension or the top-up from the Bienestar Fund.
Open group models and simulation
Project the contributors and pensioners of an entire system, the basis of the IMSS and ISSSTE valuations. With stochastic scenarios for rates, inflation and returns they measure the full distribution of funding, beyond the central scenario.
Br is the projected benefit at retirement age r, s the service at the valuation date, S the total service at r, v = 1/(1+i) the discount factor and r-xpx(τ) the probability of remaining in service from x to r given all causes of exit.
S0 is the current balance, j the return net of fees, at the contribution rate in year t (which reaches 15% in 2030) and Wt the annual contribution base salary.
P is the monthly pension that the balance ST buys; äx(12) is the whole life annuity-due payable monthly at age x, using the insurer’s mortality table and technical interest rate.
Regulatory framework in Mexico
IMSS · Ley del Seguro Social (Social Security Law, Ley 73 and Ley 97)
Sets the pension requirements of each regime, preservation of rights, voluntary continuation (Modalidad 40) and, since the 2020 reform, the schedule of minimum weeks and retirement contributions.
CONSAR · LSAR and registration of private plans
Regulates the Afores, the SIEFORES investment regime and the fee cap, and keeps the electronic register of company pension plans. In April 2026 it tightened the requirements for the actuary who certifies them: cédula profesional, at least five years in consulting and current certification.
CINIF · NIF D-3 (and IASB · IAS 19)
Requires the projected unit credit method and a discount rate based on high-quality corporate bonds in a deep market or, failing that, on government bonds. Unlike IAS 19, NIF D-3 recycles remeasurements from OCI to profit or loss based on the average remaining working life.
CNSF · LISF and CUSF (pension insurance)
Insurers that pay annuities arising from the social security laws set up reserves on technical bases supervised by the CNSF (National Insurance and Surety Commission), and the actuary who signs the valuation must be registered and hold current certification.
Decree creating the Bienestar Fund (DOF, May 1, 2024)
It is funded, among other sources, by unclaimed balances in the accounts of people aged 70 or older (IMSS) and 75 or older (ISSSTE), who retain their right to claim them. Its long-term sufficiency is an open actuarial problem.
Case study: NIF D-3 obligation for a lump-sum retirement plan
A company pays, on retirement at 65, one month of final salary for each year of service. We value a 45-year-old employee with 15 years of service (she joined at 30, so at 65 she will have 35) and a monthly salary of 40,000 pesos. Assumptions: salary increases of 4.5% a year, a discount rate of 9.5% and a probability of remaining in service to age 65 of 0.55 (mortality, disability and turnover combined).
- Projected final salary: 40,000 × 1.04520 = 96,468.56 pesos a month.
- Projected benefit at 65: 35 × 96,468.56 = 3,376,399.63 pesos.
- Present value of the total benefit: 3,376,399.63 × 1.095-20 × 0.55 = 3,376,399.63 × 0.162824 × 0.55 = 302,366.83 pesos.
- Accrued obligation (15 of 35 years): 302,366.83 × 15/35 = 129,585.79 pesos. Current service cost: 302,366.83 / 35 = 8,639.05 pesos; interest cost: 129,585.79 × 9.5% = 12,310.65 pesos.
- Sensitivity: at a rate of 8.5% the OBD rises to 155,684.36 pesos (20.1% higher) and at 10.5% it falls to 108,042.39 pesos (16.6% lower). The asymmetry reflects the convexity of a 20-year cash flow.
Where they work and how they grow
Cleans employee census data, runs valuations, reconciles results against the prior year and prepares the report tables. Learns to explain every change in the obligation.
Manages the technical relationship with clients, proposes assumptions, deals with the external auditor and carries out plan design and Modalidad 40 studies. Usually becomes certified in contingent employee benefit liabilities.
Signs valuations, leads ALM and plan conversion studies and reviews the team’s work. At Afores or insurers, heads product, reserving or risk.
Sets the strategy of the retirement practice, advises pension committees and boards and answers for the technical quality of everything the team signs.
- Actuarial consulting firms specializing in employee benefits
- Afores (investments, risk and products)
- Pension insurers and life annuity units
- IMSS and ISSSTE (finance and actuarial studies)
- CONSAR and the Secretaría de Hacienda (Ministry of Finance)
- Corporations with their own plans (compensation and benefits)
- State pension systems and public universities
- Banks acting as trustees for company pension funds
Skills and tools
Technical
Tools
Personal
Certification and training
CONAC certification in contingent employee benefit liabilities
AMAC, the pensions arm of the Colegio Nacional de Actuarios, administers the exams and CONAC grants the certification. It is the benchmark credential for NIF D-3 valuations and plans registered with CONSAR. See certification.
AMAC membership
The Asociación Mexicana de Actuarios Consultores (Mexican Association of Consulting Actuaries) brings together those who value employee benefit liabilities and organizes continuing education and discussion of technical criteria.
CONAC certification in life insurance
Required, together with registration with the CNSF, to sign technical notes or reserve valuations at insurers, including life annuity insurers.
SOA · FSA in Retirement Benefits
The Society of Actuaries track specializing in retirement, valued at global consulting firms and at subsidiaries that report under US GAAP.
Trends reshaping the field
The Afore generation reaches retirement
With fewer weeks required and rising contributions, more Ley 97 workers will qualify for a pension every year. Demand is growing for individual projections, decumulation advice and calculation of the guaranteed minimum pension and the top-up from the Bienestar Fund.
Sustainability of the Bienestar Fund
The top-up to the average salary creates a public obligation that depends on unclaimed accounts and federal transfers. Measuring its sufficiency is an open group problem of interest to the Ministry of Finance, Congress and independent analysts.
Longevity and the annuity market
Mortality improvement makes life annuities more expensive and puts pressure on pension insurers’ reserves. Tables with dynamic improvement are under discussion, as are products that combine programmed withdrawal with a deferred annuity.
Defined contribution under closer supervision
Companies keep closing defined benefit plans while CONSAR tightens plan registration to curb schemes that disguise pay as pensions and shrink the tax base. The actuary gains weight as the technical guarantor that a plan is genuine and funded.
Frequently asked questions
What is the difference between Ley 73 and Ley 97?
Is Modalidad 40 worth it?
What do I need to work on NIF D-3 valuations?
Does the 2020 reform guarantee adequate pensions?
Further reading
- Banco de México: La reforma del sistema de pensiones de México (box, 2021)
- DOF: Decree creating the Bienestar Fund (May 1, 2024)
- Proceso: 2026 threshold of the Bienestar Fund
- Infobae: Modalidad 40 in 2026, contributions and requirements
- IMEF: Technical bulletin on NIF D-3 Employee Benefits
- IDC: CONSAR changes to the register of private pension plans (2026)
- Lockton: Bienestar Fund, implications for employers