Section 20. A society may grant paid-up nonforfeiture benefits, cash surrender values, certificate loans and such other options as its by-laws may permit. As to each certificate issued, a society shall grant at least one paid-up nonforfeiture benefit, except in the case of pure endowment, annuity or reversionary annuity contracts, reducing term insurance contracts or contracts of term insurance of uniform amount of fifteen years or less expiring before age sixty-six.

In the case of certificates other than those for which reserves are computed on the Commissioners 1941 Standard Ordinary Mortality Table, the Commissioners 1941 Standard Industrial Mortality Table, the Commissioners 1958 Standard Ordinary Mortality Table, or such later tables as are authorized for use by domestic life insurers and approved by the commissioner, the value of every paid-up nonforfeiture benefit and the amount of any cash surrender value, loan or other option granted shall not be less than the excess, if any, of (a) over (b) as follows:

(a) The reserve under the certificate determined on the basis specified in the certificate; and

(b) The sum of any indebtedness to the society on the certificate, including interest due and accrued, and a surrender charge equal to two and one-half per cent of the face amount of the certificate, which, in the case of insurance on the lives of children, shall be the ultimate face amount of the certificate, if death benefits provided therein are graded.

However, in the case of certificates issued on a substandard basis, or in the case of certificates, the reserves for which are computed upon the American Men Ultimate Table of Mortality, the term of any extended insurance benefit granted, including accompanying pure endowment, if any, may be computed upon the rates of mortality not greater than one hundred and thirty per cent of those shown by the mortality table specified in the certificate for the computation of the reserve.

In the case of certificates for which reserves are computed on the Commissioners 1941 Standard Ordinary Mortality Table, the Commissioners 1941 Standard Industrial Mortality Table, the Commissioners 1958 Standard Ordinary Mortality Table, or such later tables as are authorized for use by domestic life insurers and approved by the commissioner, every paid-up nonforfeiture benefit and the amount of any cash surrender value, loan or other option granted shall not be less than the corresponding amount ascertained in accordance with the provisions of the laws of the commonwealth applicable to life insurance companies issuing policies containing life insurance benefits based upon such tables.