X-rays must be reasonably proximate to the initiation of a course of treatment. Unless more specific X-ray evidence is warranted, an X-ray is considered reasonably proximate if it was taken no more than 12 months prior to or 3 months following the initiation of a course of chiropractic treatment.
In certain cases of chronic subluxation (e.g., scoliosis), an older X-ray may be accepted provided the beneficiary's record indicates the condition existed longer than 12 months and there is a reasonable basis for concluding the condition is permanent.